O - Word Building Reference

Medical terminology is composed of a prefix, root word, and suffix:
Prefix: A prefix is placed at the beginning of a word to modify or change its meaning. Pre means "before." Prefixes may also indicate a location, number, or time.
Root: central part of a word.
Suffix: The ending part of a word that modifies the meaning of the word.
Additional resources: [Intro to med terms] [Med terms rules] [Med term reference] [Word building reference] [Practice Exams]

Medical Terminology Reference

Use this reference to see how common medical terms are created using the various prefixes, suffixes, and root words.

obstetrics

Prefix:
Prefix Definition:
1st Root Word: obstetr/o
1st Root Definition: pregnancy; birth
2nd Root Word:
2nd Root Word Definition:
Suffix: -ic
Suffix Definition: pertaining to
Definition: pertaining to the care of a woman during pregnancy and after
the birth

oculist

Prefix:
Prefix Definition:
1st Root Word: ocul/o
1st Root Definition: eye
2nd Root Word:
2nd Root Word Definition:
Suffix: -ist
Suffix Definition: specialist
Definition: specialist in the disease and treatment of the eye

oligotrophy

Prefix:
Prefix Definition:
1st Root Word: olig/o
1st Root Definition: scanty
2nd Root Word: troph/o
2nd Root Word Definition: nourishment; development
Suffix: -ic
Suffix Definition: pertaining to
Definition: pertaining to nutrition deficiency

omphalectomy

Prefix:
Prefix Definition:
1st Root Word: omphal/o
1st Root Definition: umbilicus (navel)
2nd Root Word:
2nd Root Word Definition:
Suffix: -ectomy
Suffix Definition: removal; excision; resection
Definition: surgical removal; excision; resection of the navel

oncologist

Prefix:
Prefix Definition:
1st Root Word: onc/o
1st Root Definition: tumor
2nd Root Word:
2nd Root Word Definition:
Suffix: -logist
Suffix Definition: specialist in the study of
Definition: specialist in the diagnosing and treatment of cancer

oncology

Prefix:
Prefix Definition:
1st Root Word: onc/o
1st Root Definition: tumor
2nd Root Word:
2nd Root Word Definition:
Suffix: -logy
Suffix Definition: study (process of)
Definition: study of tumors

onychomycosis

Prefix:
Prefix Definition:
1st Root Word: onch/o
1st Root Definition: nail (of fingers or toes)
2nd Root Word: myc/o
2nd Root Word Definition: fungus
Suffix: -osis
Suffix Definition: condition, usually abnormal
Definition: abnormal condition of a fungal infection of the finger or toe nails

onychophagy

Prefix:
Prefix Definition:
1st Root Word: onch/o
1st Root Definition: nail (of fingers or toes)
2nd Root Word: phag/o
2nd Root Word Definition: eat; swallow
Suffix: -y
Suffix Definition: condition; process
Definition: condition of biting; eating finger or toe nails

oogenesis

Prefix:
Prefix Definition:
1st Root Word: o/o
1st Root Definition: egg
2nd Root Word:
2nd Root Word Definition:
Suffix: -genesis
Suffix Definition: producing; forming
Definition: producing; forming of the ovum (egg cell)

oophorectomy

Prefix:
Prefix Definition:
1st Root Word: oophor/o
1st Root Definition: ovary
2nd Root Word:
2nd Root Word Definition:
Suffix: -ectomy
Suffix Definition: removal; excision; resection
Definition: surgical removal; excision; resection of an ovary

ophthalmology

Prefix:
Prefix Definition:
1st Root Word: ophthalm/o
1st Root Definition: eye
2nd Root Word:
2nd Root Word Definition:
Suffix: -logy
Suffix Definition: study (process of)
Definition: study of treatment and disease of the eye

optometrist

Prefix:
Prefix Definition:
1st Root Word: opt/o
1st Root Definition: eye; vision
2nd Root Word:
2nd Root Word Definition:
Suffix: -ist
Suffix Definition: specialist
Definition: specialist in the treatment and disease of the eye

optometry

Prefix:
Prefix Definition:
1st Root Word: opt/o
1st Root Definition: eye; vision
2nd Root Word:
2nd Root Word Definition:
Suffix: -metry
Suffix Definition: process of measuring
Definition: process of measuring the eye’s strength and range

oral

Prefix:
Prefix Definition:
1st Root Word: or/o
1st Root Definition: mouth
2nd Root Word:
2nd Root Word Definition:
Suffix: -al
Suffix Definition: pertaining to
Definition: pertaining to the mouth

orchiectomy

Prefix:
Prefix Definition:
1st Root Word: orchi/o
1st Root Definition: testis
2nd Root Word:
2nd Root Word Definition:
Suffix: -ectomy
Suffix Definition: removal; excision; resection
Definition: surgical removal; excision; resection of the testis

orthodontist

Prefix:
Prefix Definition:
1st Root Word: orth/o
1st Root Definition: straight
2nd Root Word: odont/o
2nd Root Word Definition: tooth
Suffix: -ist
Suffix Definition: specialist
Definition: specialist in the straightening of teeth

osseous

Prefix: osse-
Prefix Definition: bony
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -ous
Suffix Definition: pertaining to
Definition: pertaining to or composed of bone

osteoarthritis

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word: arthr/o
2nd Root Word Definition: joint
Suffix: -itis
Suffix Definition: inflammation
Definition: deterioration of joint cartilage and the underlying bone (a form of
arthritis)

osteochondritis

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word: chondr/o
2nd Root Word Definition: cartilage
Suffix: -itis
Suffix Definition: inflammation
Definition: inflammation of the bone and cartilage

osteoclasis

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -clasis
Suffix Definition: to break
Definition: surgical break down of bone tissue

osteogenesis

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -genesis
Suffix Definition: producing; forming
Definition: formation of bone

osteomalacia

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -malacia
Suffix Definition: softening
Definition: softening of bone

osteopathy

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -pathy
Suffix Definition: disease; emotion
Definition: disease of bone

osteopenia

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -penia
Suffix Definition: deficiency
Definition: deficiency of bone mass

osteoporosis

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -porosis
Suffix Definition: condition of pores (spaces)
Definition: condition of weak; porous; brittle bones

osteosarcoma

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word: sarc/o
2nd Root Word Definition: flesh (connective tissue)
Suffix: -oma
Suffix Definition: tumor; mass; fluid collection
Definition: malignant tumor of bone

osteotomy

Prefix:
Prefix Definition:
1st Root Word: oste/o
1st Root Definition: bone
2nd Root Word:
2nd Root Word Definition:
Suffix: -tomy
Suffix Definition: process of cutting
Definition: surgical process of cutting bone

otology

Prefix:
Prefix Definition:
1st Root Word: ot/o
1st Root Definition: ear
2nd Root Word:
2nd Root Word Definition:
Suffix: -logy
Suffix Definition: study (process of)
Definition: study of the ear and it’s diseases

ovariectomy

Prefix:
Prefix Definition:
1st Root Word: ovari/o
1st Root Definition: ovary
2nd Root Word:
2nd Root Word Definition:
Suffix: -ectomy
Suffix Definition: removal; excision; resection
Definition: surgical removal; excision; resection of the ovary

ovogenesis

Prefix:
Prefix Definition:
1st Root Word: ov/o
1st Root Definition: egg
2nd Root Word:
2nd Root Word Definition:
Suffix: -genesis
Suffix Definition: producing; forming
Definition: producing or forming of an ovum

Navigation

Check out the following resources to support your learning and understanding of medical terminology:

Quick Introduction– provides an overview and introduction to medical terminology.
Medical Terms – Prefixes, roots, suffixes – Alphabetical listing of Med Terms.
Medical Terms – Rules governing singular versus plural versions of medical terms are described.
Medical Terminology Exams– twenty new exams were created to test your knowledge of medical terminology.

Word building reference [ O ]

Alphabetical Listing (word building)